MESOSCALE PRECIPITATION DISCUSSION 0144
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
455 PM EDT MON MAY 14 2018

AREAS AFFECTED...SOUTHEAST KANSAS

CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE

VALID 142053Z - 150200Z

SUMMARY...PERSISTENT THUNDERSTORMS LATE THIS AFTERNOON AND EARLY
THIS EVENING MAY LEAD TO FLASH FLOODING. RAIN RATES OF 1-2 IN/HR
WILL BE LIKELY WITH LOCALIZED RAINFALL POSSIBLY IN EXCESS OF 4
INCHES.

DISCUSSION...A CONVECTIVE CLUSTER HAS CONTINUED TO MAINTAIN ITS
STRENGTH AND ORGANIZATION WHILE REMAINING RELATIVELY STATIONARY
FROM NORTHERN GREENWOOD COUNTY KS...TO NEAR THE ANDERSON-ALLEN
COUNTY (KS) BORDER. MRMS RAIN RATE ESTIMATES ARE NOW AS HIGH AS 2
IN/HR...AND THE CLUSTER WHICH PREVIOUSLY FEATURED GAPS BETWEEN
INDIVIDUAL CONVECTIVE CELLS HAS CONSOLIDATED BETWEEN 20Z AND 21Z.
THE MORE CONTINUOUS AREA OF REFLECTIVITY NEAR OR ABOVE 50 DBZ
SHOULD LEAD TO HEAVY RAINFALL FOR MORE THAN AN HOUR...PARTICULARLY
NEAR THE CENTER OF THE CLUSTER (NEAR NEOSHO FALLS KS AS OF 2045Z).
THEREFORE...A NEAR-TERM FLASH FLOOD THREAT APPEARS TO EXIST BASED
ON RECENT RADAR TRENDS ALONE.

THE CONVECTIVE CLUSTER IS SITUATED NEAR AN AXIS OF LOW-LEVEL
CONVERGENCE...EVIDENT IN THE SURFACE WIND OBSERVATIONS. THIS
CONVERGENCE ZONE IS EXPECTED TO REMAIN ACTIVE INTO THE EARLY
EVENING HOURS...WITH HI-RES MODELS SHOWING RENEWED CONVECTION NEAR
OR JUST UPSTREAM OF THE ONGOING CLUSTER AROUND 23-01Z...WITH
ADDITIONAL CONVECTION POSSIBLE SW ALONG THE BOUNDARY INTO
NORTH-CENTRAL OKLAHOMA. PRECIPITABLE WATER VALUES ESTIMATED BY THE
CIRA BLENDED TPW...AND MEASURED BY THE 17Z LAMONT OK
SOUNDING...ARE AROUND 1.5 INCHES...WHICH IS NEAR THE 90TH
PERCENTILE FOR MID MAY. THE AREA IS ALSO IN AN AREA OF DIFFLUENT
THICKNESS LINES...OFTEN A REGION FAVORED FOR FLASH FLOODING AND
POTENTIALLY REDUCED CELL MOTION. INDEED BACKBUILDING CORFIDI
VECTORS ARE ONLY AROUND 10 KNOTS AND THIS IS FURTHER SUPPORTED BY
RECENT RADAR TRENDS. THEREFORE FURTHER TRAINING APPEARS POSSIBLE
(MEAN WIND ALIGNED WITH CONVERGENCE ZONE) AND SLOW STORM MOTIONS
MAY INCREASE THE RESIDENCE TIME OF HEAVY RAIN. FLASH FLOODING IS
POSSIBLE IN THE REGION...AND MAY BECOME MORE LIKELY IF THE RENEWED
CONVECTIVE DEVELOPMENT CLOSER TO THE TIME OF THE EVENING INCREASE
IN THE LLJ OCCURS OVER AREAS THAT HAVE ALREADY EXPERIENCED HEAVY
RAINFALL.

LAMERS

ATTN...WFO...EAX...ICT...OUN...SGF...TOP...

ATTN...RFC...ABRFC...MBRFC...

LAT...LON   38619483 38269411 37669444 37369549 37109656
            36599759 36879794 37489780 38149718 38569631